The basal vein is formed at the anterior perforated substance by the union of (a) a small anterior cerebral vein which accompanies the anterior cerebral artery, (b) the deep middle cerebral vein (deep Sylvian vein), which receives tributaries from the insula and neighboring gyri, and runs in the lower part of the lateral cerebral fissure, and (c) the inferior striate veins, which leave the corpus striatum through the anterior perforated substance. The basal vein passes backward around the cerebral peduncle, and ends in the internal cerebral vein (vein of Galen); it receives tributaries from the interpeduncular fossa, the inferior horn of the lateral ventricle, the hippocampal gyrus, and the mid-brain.

The Internal Cerebral Veins (vv. cerebri internæ; veins of Galen; deep cerebral veins) drain the deep parts of the hemisphere and are two in number; each is formed near the interventricular foramen by the union of the terminal and choroid veins. They run backward parallel with one another, between the layers of the tela chorioidea of the third ventricle, and beneath the splenium of the corpus callosum, where they unite to form a short trunk, the great cerebral vein; just before their union each receives the corresponding basal vein.

The terminal vein (v. terminalis; vena corporis striati) commences in the groove between the corpus striatum and thalamus, receives numerous veins from both of these parts, and unites behind the crus fornicis with the choroid vein, to form one of the internal cerebral veins. The choroid vein runs along the whole length of the choroid plexus, and receives veins from the hippocampus, the fornix, and the corpus callosum.

The Great Cerebral Vein (v. cerebri magna [Galeni]; great vein of Galen) (Fig. 565), formed by the union of the two internal cerebral veins, is a short median trunk which curves backward and upward around the splenium of the corpus callosum and ends in the anterior extremity of the straight sinus.

The cerebellar veins are placed on the surface of the cerebellum, and are disposed in two sets, superior and inferior. The superior cerebellar veins (vv. cerebelli superiores) pass partly forward and medialward, across the superior vermis, to end in the straight sinus and the internal cerebral veins, partly lateralward to the transverse and superior petrosal sinuses. The inferior cerebellar veins (vv. cerebelli inferiores) of large size, end in the transverse, superior petrosal, and occipital sinuses.